- Streams
A stream lets you describe what you want done to a collection instead of writing the loop that does it. It is the single biggest change in how Java is written since Java 8, and the mental model is small: a source, some intermediate operations, and one terminal operation that makes it all run. The…
- Method References
A method reference is a lambda with the noise removed. When a lambda does nothing but call one existing method, :: lets you name that method instead of describing the call. They compile to the same thing — the method reference is not faster, and it is not a different mechanism. It is the same…
- Big O Notation
How an algorithm's cost grows as the input grows — the only performance question that survives a change of hardware. The common classes from O(1) to O(2^n), how to read a complexity off a loop, why constants are dropped, and the difference between time and space complexity.
- Spring Boot – API Docs with springdoc-openapi
Springfox is dead; springdoc is what generates OpenAPI 3 from your controllers now. Wiring it up, documenting an endpoint properly, describing JWT auth so the Try It Out button works — and the version pin Boot 4 forces on you, because Boot no longer manages springdoc's version.
- React Native – Animations and the Native Driver
The `Animated` API, and the one flag that matters: `useNativeDriver`. With it the animation runs on the UI thread and stays smooth while JavaScript is busy; without it every frame crosses the bridge. Which properties can be driven natively and which cannot, `interpolate`, starting an animation in an effect rather than in render, and where Reanimated takes over.